This metal detector-the ‘Pirate’- was originally designed by a Russian forum.It’s a pulse induction (PI) type detector.
basic components are :
Integrated circuits : NE555 – 1 pc and TL072 – 1 pc ;
Transistors: IRF740, BC557, BC639 ;
Diodes: in4148 – 2 pcs, in5819 – 1 pc;
Variable resistor – 2 pcs (500 kΩ, 50 kΩ);
Trimpot resistor – 1 pc (200kΩ)
Resistors – 14 pcs;
Ceramic capacitors – 3 pcs;
Electrolytic capacitors – 5 pcs;
PCB 70 x 30 mm;
Sockets for chips 8pin – 2 pcs ;
Switch;
The handle under the variable resistor – 2 pieces ;
Computer cable “twisted pair” (3 meters) or wire sew, PEL, PETV, etc. (F 0.3-0.7 mm);
Battery 9-12 V;
Headphones or speaker.